FAW Transmission Auxiliary Mounting Logic Assembly: An Expert Focus on 17 Critical Components

Welcome to this expert technical guide on the FAW Transmission Auxiliary Mounting Logic Assembly. This is the complete, heavy-duty support system for the main gearbox, designed for the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is not the transmission itself, but the critical “suspension” that holds it.

The FAW Transmission Auxiliary Mounting Logic Assembly provides the main structural support for the rear of the heavy transmission, connecting it to the truck’s chassis frame rails. Its “logic” is to provide a rigid, unyielding brace against engine torque while simultaneously isolating the cab from drivetrain vibration.

This in-depth guide is an essential resource for professional chassis technicians and fleet managers. We will deconstruct the entire FAW Transmission Auxiliary Mounting Logic Assembly into its 17 serviceable components, including the main ‘Crossbeam’ (1706061-95U), the ‘Flexible Cushion Assemblies’ (1704150-5H), and all the critical brackets and fasteners.

Core Structure: The Crossbeam Assembly (1706061-95U)

The backbone of the entire FAW Transmission Auxiliary Mounting Logic Assembly is the ‘Crossbeam-transmission auxiliary mounting crossbeam assy’ (1706061-95U). This is the primary structural member, a massive, heavy-gauge steel crossbeam that spans the two main frame rails of the truck’s chassis, passing directly underneath the transmission.

This crossbeam is the “stage” upon which all other components of the FAW Transmission Auxiliary Mounting Logic Assembly are built. Its function is to bear the entire static weight of the rear of the transmission (which can be several hundred kilograms) and, more importantly, to resist the immense rotational “torque-twist” of the powertrain when the driver accelerates. A crack or bend in this crossbeam would compromise the entire driveline angle and is a critical structural failure.

Chassis-Side: The Fixed Bracket Assemblies

The ‘Crossbeam’ (1706061-95U) connects to the truck’s main frame rails via a set of fixed brackets. This parts list details the ‘Left fixed bracket-transmission auxiliary mounting crossbeam assy’ (1706063-95U) and the ‘Right fixed bracket-transmission auxiliary mounting crossbeam’ (1706064-95U).

These are heavy-duty, forged or fabricated steel brackets. They act as the non-moving interface, bolting directly to the side of the truck’s C-channel frame rail. The crossbeam is then bolted to these brackets. This multi-piece design (bracket + crossbeam) is a key part of the FAW Transmission Auxiliary Mounting Logic Assembly “logic,” as it allows for easier installation and service compared to a single, full-width welded unit.

These fixed brackets are secured to the frame with the ‘Hex flange bolt, coarse rod (Standard Type)’ (Q1841440) and ‘Large washer’ (Q40214) hardware. The entire FAW Transmission Auxiliary Mounting Logic Assembly relies on this rigid, no-flex connection to the chassis.

The “Logic”: Flexible Cushion Assembly (1704150-5H)

The most critical “logic” of the FAW Transmission Auxiliary Mounting Logic Assembly lies in the ‘Transmission mounting flexible cushion assy’ (1704150-5H). The parts list calls for four of these. These are the main “transmission mounts,” or vibration isolators.

It is a common mistake to think the engine and transmission should be bolted rigidly to the frame. This would transmit 100% of the engine’s vibration directly into the chassis and cab, resulting in an unbearably loud, bone-jarring ride and causing metal components to fatigue and crack.

These “flexible cushions” are the solution. Each one is a “sandwich” of high-strength steel and a large block of specially-engineered rubber (elastomer). The ‘Left auxiliary support bracket’ (1706071-97V) and ‘Right auxiliary support bracket’ (1706072-97V) bolt to the transmission itself. These brackets then rest *on* these four flexible cushions. The cushions, in turn, rest on the main ‘Crossbeam’ (1706061-95U).

The rubber in these mounts is designed to absorb and “dampen” the high-frequency vibrations of the powertrain, while still being stiff enough to resist the “push-pull” of torque. A failed cushion (e.g., collapsed or “de-bonded” rubber) is a critical failure of the FAW Transmission Auxiliary Mounting Logic Assembly, resulting in a severe “clunk” on acceleration and excessive vibration in the cab. The entire FAW Transmission Auxiliary Mounting Logic Assembly is designed around these four cushions.

Gaskets, Plates, and Sleeves

To support the “flexible cushion” logic, the FAW Transmission Auxiliary Mounting Logic Assembly uses several other components. The ‘Gasket block-transmission auxiliary mounting bracket’ (1706073-91W) and ‘Gasket plate-transmission auxiliary support crossbeam assy’ (1706062-48A) are critical insulators.

These pads (or “gaskets”) are made of a dense polymer or rubber. They are placed between the steel mounting brackets (e.g., 1706071-97V) and the transmission housing. This prevents any direct metal-on-metal contact, which would transmit noise and vibration, bypassing the main cushions.

The ‘Support sleeve’ (1704166-5H) is a steel tube that passes *through* the center of the ‘Flexible cushion’ (1704150-5H). This is a critical component that acts as a “stop.” It allows the technician to tighten the main mounting bolts (like Q1841455T) with full torque, making the steel-on-steel connection (bolt-to-sleeve-to-bracket) rigid, *without* “crushing” the rubber of the flexible cushion. This is the key to the entire FAW Transmission Auxiliary Mounting Logic Assembly‘s design.

Critical Fasteners: The Locking Pin System

The FAW Transmission Auxiliary Mounting Logic Assembly is a high-vibration area, and a loose fastener is not an option. The list details a critical “cannot-fail” locking system for the main support pins.

The ‘Hex head bolt with hole’ (CQ17716110), of which there are two, are special bolts. They are used to secure the ‘Left’ and ‘Right’ auxiliary support brackets to the transmission. As the name implies, a hole is drilled through the bolt’s head.

After this bolt is torqued to its final specification, the ‘Cotter pin’ (Q5003040) is inserted through this hole and its “legs” are bent over. This small pin acts as a 100% positive, physical lock. It makes it mechanically impossible for the bolt to vibrate loose and back out. This “bolt-and-castle-nut-with-pin” logic (though here it’s a bolt-with-pin) is the ultimate in safety and is a hallmark of the FAW Transmission Auxiliary Mounting Logic Assembly‘s robust design.

FAW Transmission Auxiliary Mounting Logic Assembly Parts List

The following table provides the complete, detailed breakdown of all 17 components identified in the ‘Transmission Auxiliary Mounting Logic Assembly’ diagram for the FAW CA4251P66K24T1A3E5 tractor. This FAW Transmission Auxiliary Mounting Logic Assembly is the key to a smooth, vibration-free ride.

Technical Specifications and Assembly Context

The specifications for the FAW Transmission Auxiliary Mounting Logic Assembly are defined by its function as a heavy-duty, vibration-damping structural support. The entire FAW Transmission Auxiliary Mounting Logic Assembly is key to driveline alignment and driver comfort.